Reproducing and transmitting apparatus.



J. J. COMER.

REPRODUCING AND TRANSMITTING APPARATUS.

APPLICATION FILED JAN-27, 1912.

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UNITED STATES PATENT OFFICE.

JOHN J'. COMER, OF CHICAGO, ILLINOIS, ASSIGNOR T0 AUTOMATIC ENUNCIATOR COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

REPRODUCING AND TRANSMITTING APPARATUS.

Specification of Letters Patent.

Patented June 6, 1916.

Application filed January 27', 1912. Serial No- 673,941.

To all whom it may concern:

Be it known that I,'JOHN J. Common, a citizen of the United States of America, and resident of Chicago, Cook county, Illinois, have invented a certain new and useful Improvement in Reproducing and Transmitting Apparatus, of which the following is a specification.

, My invention relates to an improved reproducing and transmitting apparatus, and is particularly adapted for reproducing the vibrations received from a record, and then transmitting these vibrations to a distant point where they are reproduced into articulate sounds.

My invention is especially useful in 0on nection with reproducing musical sounds from a phonograph record. In such apparatus very careful and delicate ad ustment and construction are necessary in order to obtain a clear reproduction of the music from the record. .It is necessary that extraneous vibrations be entirely eliminated.

- It is furthermore necessary that the vibrationsof the diaphragm be controlled in such manner that this diaphragm does not have any false vibrations. Heretofore the diaphragm has either been uncontrolled, in which case these false vibrations were bound to occur, or else the diaphragm has been controlled by metallic springs. In this last instance, while the false vibrations of the diaphragm were eliminated, still the presence of the metallic springs caused a metallic sound which was very objectionable.

I One of the important features of my in- I vention is toentirely eliminate these ob ectionable features, by providing non-metallic controlling means for the diaphragm by which all extraneous vibrations are eliminated, and in which this objectionable metallic sound is avoided.

A further feature of my invention is the improved manner of mounting the microphone transmitter, so that the variable resistance material is afiected solely by the vibrations received from the record and in which these microphones are not affected by other extraneous'vibrations.

A still further feature of my invention is in the manner of mounting the reproducing and transmitting apparatus. In this class of apparatus in which the needle supports the transmitting box, it has been found that in order to get the best results the weight actually supported by the needle should not be more than four and one-half (4%) ounces. As my apparatus is heavier Elan this, I so support it on thisarm that this supported arm; partially carries the weight of the transm1tt1ng box, the amount left for the needle to support being substantially four and onehalf (4%) ounces.

A further feature is in having the transmitting apparatus so mounted that it may be turned upward so as to bring the needle into position whereby it can be more readily changed. This upsetting of the transmitter box is also advantageous as it prevents the carbon from packing.

These and other objects and features of my invention will be more readily understood by having reference to the accompanying drawings, in which- Figure 1 is a side elevation of my appara tus with one of the microphone transmitters and the associated felt packing removed in order to more clearly show the manner in which the mounted arm is secured to the apparatus. Fig. 2 is a cross sectional view of the complete apparatus. Fig. 3 is a detail bottom view. Fig. 4 is a sectional view taken on line 4l in Fig. 3.

I- have illustrated a supporting arm 5 having an upturned end portion 6 to which the disks 8 and 9 of the transmitting apparatus are pivoted at the point 7. This supporting arm 5 is likewise provided with a knuckle joint 10. By this means the transmitting apparatus can first be swung about the pivot point 7, and then by means of this knuckle joint 10 the transmitting apparatus can be swung back so as to rest upon the upper side of the supporting arm in the manner shown in dotted lines in Fig. 1. By this construction the needle is brought into position whereby it can be readily changed. And, furthermore, the carbon of the microphone, to be hereinafter described, is upset so as to prevent packing.

Located upon-the outside of each of the disks 8 and 9, there is a microphone transmitter. Each of these transmitters are separated from the respective disk by means of a felt packing 15. The two microphones are similar in construction and consist of the diaphragm 16 upon opposite sides of which are mounted bodies of granular material 17. This granular material covers the central portion of the diaphragm while the marginal portions are surrounded by a restricted air space formed by the clamping plates 18.

The particular type of transmitter employed is not an essential feature of my present invention, although I have found that very eflicient results are obtained by means of the transmitter here shown and described. The parts are held together by means of three through bolts 19. These bolts are surrounded by a felt packing 20. By this construction-that is, by the employment of the felt packing 15 between the disks 8 and 9 and the microphone transmitter, and by means of the felt packing about the through bolt 19--I provide a very efiicient construction, as by this means it is practically impossible for the diaphragm 16 of the microphone transmitters to be vibrated by any foreign or extraneous vibrations of the disks 8 and 9., The use of this felt packing provides a very loose and flexible connection between these parts, so that the vibrations of the diaphragm are entirely caused by the vibrations received through the air from the diaphragms 12 and 13.

Located between the diaphragms 12 and 13, and secured thereto, there is mounted the reproducing arm 21. This arm is provided at its lower end with a socket for holding the needle 22 in the usual manner. This needle 22 is adapted to traverse a grooved record, such as shown at 23 in Fig. 1, and to be vibrated laterally thereby. Mounted upon this reproducing arm is a bearing plate 23, which bearing plate pivots on two trunnion points 24:. If this reproducing arm, which is connected to the diaphragms 12 and 13, was allowed to vibrate freely, the rapid vibrations would tend to set up false vibrations in the diaphragm and the arm, and thus interfere greatly with the clear and exact transmission of the music or other sounds from the record. In order to avoid .this, I provide means for controlling the via circular opening 26; passing through this opening there is a screw bolt 27 which bolt is separated from the plate 23 by means of the rubber washer 28. I have likewise shown a second washer 29 located between the head of the bolt and the rubber washer 28, although it is not necessary that this second washer be of non-metallic material. A look nut 30 is mounted on the bolt 27, so as to lock this bolt in any desired position. It will be noticed that the opening 26 is of suflicient dimension so that the lock nut does not touch the bearing plate 23 at any point. By this construction it will be noticed that by adjusting the bolt 27 the rubber washer 28 can be made to bear with greater or less pressure upon the laterally extending ears of the bearing plate 23. This pressure is so adjusted as to damp the vibrations of the reproducing arm to the proper extent. As this arm is vibrated on the trunnion points 24, the ears 25 move toward and away from the rubber washer 28, this washer being of suflicient flexibility to permit of this slight vibration of the bearing plate caused by the record. While I have shown a rubber washer, and obtained very efficient results with such a construction, it is obvious that, if desired, very good results might be obtained with other non-metallic substances, such as felt or leather. It is essential, however, that no metal touch the vibrating arm, as any such metal will cause an objectionable metallic sound.

While I have illustrated one specific embodiment of my invention, and one in which the vibrations received from the record are transmitted electrically to a distant point, it is to be understood that in certain broader aspects my invention is not limited to such use. It is obvious that my non-metallic control for the reproducing arm could be as well applied to apparatus in which the reproduction is entirely by mechanical means. Likewise while I have shown my reproducing arm in connection with a pair of diaphragms, it is to be understood, of course, that very eflicient results can be obta ned with but a single diaphragm. Many other changes and modifications will readily suggest themselves, and I consider these within the scope broadly of my invention.

What I claim as my invention is:

1. In a sound reproducing apparatus, a vibrated diaphragm, a microphone located adjacent to said diaphragm, a felt packing between said microphone and said diaphragm, through bolts for securing said microphone and diaphragm together, and felt packing surrounding said through bolts.

.2. In a sound reproducing apparatus, a diaphragm, a pair of microphone transmitters located on opposite sides of said diaphragm, felt packing located between said transmitters and said diaphragm, through bolts for securing said microphones and diaphragm together, and felt packing surrounding said through bolts.

3. In a sound reproducing apparatus, the combination of a pair of vibrated diaphragms, a common supporting ring in which said diaphragms are mounted, a microphone located on each side of said common supporting ring, a ring of felt located 10 between said supporting ring and each of said microphones, and means clamping said supporting ring, microphones and felt rings Y JOHN J. OOMER.

Witnesses:

H. A. SWENARTON, I E. H. CLEGG. 

